This invention relates to liquid flow meters of the type having at least cylindrical measuring means rotating in a measuring chamber and sliding with its end face along a bottom part of a measuring chamber in general and more particularly to an improved arrangement for such flow meters.
Liquid flow meters of this type are generally known as rotary-piston flow meters, driven-slide flow meters and oval-wheel flow meters. In a flow meter of this type if a relatively warm liquid for example a liquid at 90.degree.C, suddenly flows through the meter a danger exist that because of thermal expansion a binding of the measuring means will take place thereby damaging it. Damage can be to the extent that the measuring means must be replaced. A problem like this typically arises with meters employed in the food industry such as milk meters where a hot rinse for cleaning purposes is performed.
In view of this problem the need for a liquid flow meter which can be operated without of seizing the measuring means even where relatively warm liquid suddenly flows through the meter is clear.